Catheters are medical devices that can be inserted into a body cavity, duct, or vessel to treat diseases or perform a surgical procedure. Catheterization, for example, is performed in cardiovascular, urological, gastrointestinal, neurovascular, and ophthalmic applications. Catheters can allow drainage, administration of fluids or gases, access by surgical instruments, and perform wide variety of other tasks depending on the type of catheter. Catheters can, for instance, include energy emitting devices, such as laser and other radiation emitters, to ablate or cauterize tissue, particularly in coronary catheterization and lead removal. In most uses, catheter is a thin, flexible tube (“soft” catheter) though catheters are available in varying levels of stiffness depending on the application.
In energized catheters, such as laser catheters, it can be important to identify the catheter to an energizing base unit, such as an excimer laser system, for purposes of selecting appropriate specifications, requirements, and other operating information (such as active area, maximum and minimum allowable fluence, and repetition rate (e.g., lasing on/off time), and lasing train time) required for catheter energization. One method of identifying the catheter to the energizing base unit is to use a sequence of pins mounted to a proximal coupler of the catheter. The pin arrangement or sequence actuates switches in the catheter's coupler to generate a signal, which is forwarded to the microcontroller of the energizing base unit. Using a lookup table and the signal, the microcontroller can identify the type and/or model of the catheter and therefore the appropriate catheter specifications, requirements, and other operating information. Each type and/or model of catheter has a unique pin sequence to actuate different switches for generating different signals.
The arrangement can create problems.
First, the operating information is typically contained in firmware. When new catheters are introduced that do not correspond to the operating information already programmed in firmware, a new microcontroller must be installed containing updated code along with the operating information to operate the catheter. This can require expensive and time-consuming base unit upgrades.
Second, many catheters are disposable devices for patient health and safety. The arrangement enables unscrupulous health care providers to reuse catheters for different patients, thereby increasing the risk of infection and disease transmission
Third, one catheter manufacturer can duplicate the pin sequence of a different catheter manufacturer and thereby use the other catheter manufacturer's base unit. This situation is unsafe. The catheter manufacturer duplicating the pin sequence does not know the operating information in the base unit's firmware, thereby potentially causing the duplicated catheter to be operated using improper and unsafe operating information.